Here's what you do. Get a bunch of books. I mean a big giant stack of thick, heavy books. Take them all to the front desk to check out. Say you left your wallet in the car and just drive home, leaving them a fat stack of books to restock. Do it every week for a year.
you might think that would be a big deal, but guess what... library's pay people to shelve books! omg you brought down 20 or so books...good for you.. How many do you think the library gets on a normal day in the returns? My guess at the library I worked at was around 5,000 returns a day. Does your 20 make any difference? nope.
Have you ever even tried your own advise or are you just spouting off bullshit trying to pass yourself off as cool? Is that the best you can do? No attempt at trying to social engineer the charges off your account, or some crafty way to fool the library's computers into thinking the books aren't over do? The best you can come up with is something so childish and ineffective that's only redeeming quality is to provide me with a target to flame?
Seriously, we had security guards, we banned people for less. After that it was a trespassing charge, so you could find yourself with the rest of the lamer crazy homeless people on some do-not-library list. I know it isn't cool to you, but there is a wealth of information contained at a library. Nobody these days seems to know about it, but talk to old skewl phreakers about Library reference numbers and criss-cross directories. Hell, if you sat down with a librarian and asked the right questions I'm sure you could get the local PSAP number.